Abstract:

BACKGROUND: It is not clear whether the Cathepsis family is involved in the pathological process of early spinal cord injury and whether high-dose methylprednisolone plays neuroprotective effect through lysosome apoptosis pathway.
OBJECTIVE: To explore the expression and change of genes Cathepsin family in early spinal cord injury and to identify if high-dose methylprednisolone plays neuroprotective effect by the lysosome apoptosis pathway.
METHODS: Nine Japanese rabbits were randomly divided into three groups, the rabbits in the model group and drug treatment group were treated with laminectomy, and then the rabbits were used to establish the acute spinal cord injury model with Allen falling strike method. The rabbits in the drug treatment group were treated with human equivalent dose flushing-dose methylprednisolone at 2 hours after acute spinal cord injury. The rabbits in the control group were treated with laminectomy. All rabbits were killed at 8 hours after acute spinal cord injury, and then the damaged spinal cord tissues were obtained carefully. Total RNA was extracted from above nine samples with Trizol One-step method to undergo the examination of the gene expression profile by using Agilent Rabbit Oligo Microarray (4×44K) respectively. GeneSpring 11.0 software was then used to filter potential candidate genes, and only genes with P values ≤0.01 and fold change≥2 were retained for further analysis.
RESULTS AND CONCLUSION: The spinal cord injury models were successfully set up and the corresponding tissue specimens were obtained. Acquired nine subsample of total RNA were qualified for microarray examination. The results of microarray examination showed that among the 10 genes of Cathepsin family, only Cathepsin Z and Procathepsin E showed significant different expression. All of Cathepsin family genes of Cathepsin C, D, F, K, L, S and W did not showed significant different expression. There were no significant differences of Cathepsin family genes expressions between drug treatment group and model group after treated with methylprednisolone. Gene Cathepsin Z and Procathepsin E took part in the apoptosis of spinal cord injury at acute phase, but high-dose methylprednisolone cannot play neuroprotective effect by the lysosome apoptosis pathway.

Key words: tissue construction, basic experiment in tissue construction, spinal cord injury, methylprednisolone, lysosome, Cathepsin family gene, gene microarray, apoptosis, tissue construction photographs-containing paper